The Padma Multipurpose Bridge Project is still underway. When completed, it is expected to be the largest bridge in Bangladesh. It will connect Louhajong, Munshiganj with Shariatpur and Madaripur, linking the southwest of the country to northern and eastern regions.
This road-rail bridge across the Padma River spans approximately 6.15 km long. The upper level consists of a highway for cars, while the lower level features a railway track for trains.
The stability and durability of the bridge is a key consideration, and so the foundation design is a critical element of the project. Here, the CG680/3x8/DH grouting equipment from ChemGrout has been chosen to help strengthen the foundation of the bridge pier.
A total of five ChemGrout CG680/3x8/DH machines were provided for the project by Acme Equipment Pte Ltd, a ChemGrout dealer based in Singapore. The machines were used to carry out ‘skin grouting work’, which allows cement grout to permeate and fill the void spaces between the soil, leading to an increase in soil strength and a reduction in soil permeability.
The ChemGrout CG680/3x8/DH has a 17 cu ft homogenising colloidal mixer, a 17 cu ft agitated storage tank, and a 32 gpm grout pump. The colloidal mixing tank comes with a bridge breaker, which breaks apart the material before entering the 2X3X12 high-shear centrifugal diffuser-type pump. This pump disperses the cementitious material down to its finest particle size to achieve complete particle wetness.
The mixed material is then transferred to the CG680/3x8/DH agitator tank that is equipped with a variable speed high-efficiency paddle mixer, which will maintain a thoroughly mixed grout while waiting to be pumped. When ready, the grout will be released from the agitator tank to the connected 3x8 double plunger variable-speed output pump to inject the material into the soil.
Acme Equipment started to supply a ChemGrout machine to the project in 2016, and the grouting work has recently been completed. According to the company, every single pier has to be injected with grout from the CG680. Each pier comprises six piles, and the pile diameter is 3 m with a length of 128 m.